Compressor.



No. 719,454. PATENTED FEB. 3, 1903 W. J. FRANGKE.

COMPRESSOR. APPLICATION FILED NOV. 23, 1901.

H0 MODEL. 2 SHEETS-SHEET 1.

No. 719,454. 'PATENTED FEB. 3, 1903.

W. J. FRANGKE.

COMPRESSOR.

APPLICATION FILED NOV. 23, 1901.

H0 MODEL.

2 SHEETSSHEET 2.

UNITED STATES PATENT QFFICE.

WILLIAM J. FRANCKE, OF NEW BRUNSWIQK, NEW JERSEY, ASSIGNOR TO THEBRUNSWVICK REFRIGERATING COMPANY, OF NEWV BRUNSWICK, NElV JERSEY, ACORPORATION OF NEl/V JERSEY.

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SPECIFICATION forming part of Letters Patent No, 719,454, dated February3, 1903.

Application filed November 23, 1901. Serial No. 83,379. (No model.)

To all whom it may concern:

Be it known that I, WTLLTAM J. FRANoKE, a citizen of the United States,residing in New Brunswick, county of Middlesex, and State of New Jersey,have invented certain new and useful Improvements in Oompressors,ofwhich the following is a specification, reference being had to theaccompanying drawings, forming a part hereof.

This invention relates to compressors of the general character of that,shown in Letters Patent of the United States No. 67 7 ,503,dated July 2,1901; and it has for its object to improve the construction andoperationof such .15 compressors with especialfreference to the circulation andaction of the oil which is used as a check or cushion for the suctionand discharge valves.

One purpose incidental to the main object is to so construct thecomprornor as to adapt it particularly to conditions of use in whichthesuction-pressure remains constant and in which the discharge-pressureis also to remain constant, and particularly to make it possible torender the operation of the comprossor'automatic, so that'when thepredetermined discharge-pressure, whatever it may be, is obtained suchpressure shall be maintained without attention on the part of an op- 0orator.

Another incidental purpose is to make it possible to determine theliftof the discharge valve, so that it shall not be subject to variationduring the operation of the compressor. The invention will be more fullydescribed hereinafter With reference to the accompanying drawings, inwhich the improvements are shown as embodied in a convenient and practical form, and in Which-- Figure 1 is a view, partly in side elevationand partly in longitudinal. section, of a compressor to which theimprovements are applied. Fig. 2 is an end elevation thereof, the motorand gearing being indicated by dotted 5 lines.

The compressor illustrated in the drawings is represented as having twocylinders on opposite sides of a common crank-shaft A and secured to thecrank-casing B, which forms a part of the base or framework 13 "of theby a suitable head 13*.

compressor, the crank-shaft having a suitable bearing at C in one end ofthe crank-casing, while the other end of such casing is closed Theseveral pistons are'connected to the common crank -pin by pitmen D, andeach piston E is preferably formed as an ordinary trunk-piston. Theother-end of each cylinder F is covered by a head i in which areformedthe concentric suction and discharging valve ports. The annularsuction-port G is connected by a passage G with the crank-casing, whichthe gas or air enters at any convenient point. The end of a sleeve Grwithin the cylinder forms a valve to close the suction-port, such sleeveforming a longitudinally-removable lining in the cylinder and Withinwhich the piston moves, said sleeve being moved to a limited extent, bythe friction of the piston or by the prcisSo re of the suction-gas or byboth. At the instant the piston commences its suction-stroke a partialvacuum Will be formed in the cylinder and the sleeve will be moved .awayfrom the suction-port by the pressure of the atmosphere on theunbalanced area of the sleeve which is presented to the suctionport,thereby opening the suction-valve, and at the instant the pistoncommences its compression stroke, the cylinder being then full of air atatmospheric pressure and the two sides of the suction-valve thereforebalanced,

the sleeve will be moved toward the suctionport to close the same by thepressure of the oil against the shoulder g on the sleeve G,

as hereinafter described. 5 The central discharge-port H is connected bysuitable passages with the auxiliary air-chamber H, from which the airunder compression may be conducted to the main reservoir or place of usein any suitable manner, the discharge-port H 0 being closed by a valve HThe valve H is lifted by the pressure of the gas or air during thecompression stroke of the piston and returns again to its seat by theaction of a spring the instant that the piston commences 9 5. itssuction stroke. The lubricating-oil, which is introduced at anyconvenient point, collects in the bottom of the auxiliary chamber H, inwhich it is separated from the air which carries it after it has servedits intended pur- 10o crank-chamber in front of the pose. A pipe G whichis extended nearly to the bottom of the auxiliary chamber I'I', conveysthe oil, under the pressure of the air or gas upon its surface, to anann ular oil channel or chamber l, which is formed between a shoulderfon the cylinder 1 and a shoulder g on thesleeve G. A second annularchannel 9 is formed about the sleeveifinearer the crank-shaft, suchannular channel 9 being placed in communication with the interior of thesleeve G near its head by a channel g. A third annular channel g ispreferably formed about the sleeve G between the channel G and the headof the sleeve, such channel g also comm unicating with the channel g. Inthe operation of. the compressor describedin said Letters Patent No.677,503 when the predetermined pressure in the reservoiris attained, thepump continuing to run, the oil would be forced in the crankchamber, inwhich it would gradually accumulate, not being able to return againstthe discharge-pressure. By the provision of the channel 9?, which isplaced far enough toward the cranlcto insure the proper lubrication ofthe sleeve,the oil which is forced or escapes from the' channel Gtoward. the crank is caught, is prevented from escaping to the piston,and is returned through the channel together with that received from thechannel 9 into the space Within the sleeve alien-1v ef'the returningpiston. From this space it is discharged through the discharge-valveinto the discharge-passage, whence it returns to the auxiliaryair-chamber II, as already stated.

The compressor can therefore run indefinitely after the predeterminedpressure is attained without any attention on the part of the operator.Furthermore, as the pressure on the oil in the channel G}, as well as inthe auxiliary air-chamber II, is then the same as the predeterminedair-pressure, the sleeve G will be held from movement and thestictionvalve will cease to open. Since the opening of the suction-valvedepends upouthe relative area of the suction-valve and of the shoulder 9it becomes possible to determine the pressure at which the suction-valveshall open by varying the relative area of the shoulder 9 In buildingthe compressor it is therefore possible to fix the relative area of thisshoulder g so that the compressor shall become automatic in its actionand shall cease to increase the pressure after the predete in e'd degreehas been attained. As the or air is dis charged from the cylinder pastthe discharge valve H some of the oil which is carried with it isseparated therefrom and accun'iula'tes in the depression or receptacleindicated at f, such receptacle communicating with, the annular channelor chamber-j, fnrn'ied in the head F between the enlarged upper portion7L2 of the dischargevalve H and a shoulder f of the head F, the locationof the shoulderf being such that when the valve rests on its seat aspace is left between the ieulder f and the shoulder formed by theenlarged part 76 of the valve. This space is filled with oil underdischarge pressure, and the small quantity of oil therein serves tocushion the valve as it returns to its seat, some of the oil escapingaround the valve before the latter actually rests upon its seat. Thevalve thus cushioned is absolutely noiseless in operation, as setforthin said Letters Patent No. 677,508. Behind the enlarged portion kof the valve II is a space or chamber 71. which communicates with thechamber f through a narrow channel 72. In the movements of the valve theoil moves from one chamber f to the other, 763, through the channel 71While such channel is uncovered by the enlarged portion it" of thevalve; but as soon as the outer end of the channel 7t is covered by thevalve then the oil is imprisoned in the chamber 7L3 and resists thefurther lift of the valve, cushioning this lift, as will be apparent. Byvarying the length of the channel h, and therefore the point'at which itis cut 0E by the valve in its movement, it is possible to vary the liftoi. the valve to suit the particular conditions under which thecompressor is to be used.

The mode of operation of the present improvements will be understoodfrom the foregoing description without further explanation herein.

It will be obvious that changes in the details of construction andarrangement may be made and that the improvements may be applied tocompressors which differ in construction from that shown and describedherein without departing from the spirit of the invention.

I claim as my invention- 1. In a compressor, the combination with acylinder, a piston, a suction-valve, and a discharge-valve, of a chamberforming an oilcushiou behind the suction-valve, a chamber in front ofthe piston, a conduit to deliver oil from the chamber in front of thepiston to the first-named chamber, and a conduit to receive the oilescaping from the first-named chamber, pre ventits escape behind thepiston and return it to the second-named chamber through thedischarge-valve, whereby the oil in the firstnamed chamber is under thedischarge pressure.

2. In a compressor, the combination with a cylinder, a piston, asuction-valve, and a dis charge-valve, of a chamber forming anoilcushion behind the suction-valve, a conduit to receive the oilescaping therefrom and prevent its escape behind the piston, saidconduit terminating in the cylinder in front of the piston, and means toreturn the oil from the discharge-valve to said chamber, whereby the oilin said chamber is under the discharge pressure.

3. In a compressor, the combination with a cylinder, a piston, a sleevesuction-valve surrounding the piston and operated by the frictionthereof, and a discharge-valve, of a channel between said sleeve andcylinder nel between said sleeve and cylinder forming a chamber for anoil-cushion, a chamber in front of the piston, a condnitlto receive theoil escaping from the first-ham d chamber, prevent its escape behindhpi, ton and return it to the second-name c amber through thedischarge-valve, and means to deliver the oil from the sccond-namcdchamber to the first-named chamber.

4;. In a compressor, the combination with a cylinder, a piston, a sleevesuction-valve surrounding the piston and operated by the frictionthereof and a discharge-valve, of a chanforming a chamber for anoil-cushion, a second channel about said sleeve in rear of the firstchannel to receive the oil escaping therefrom and prevent its escapebehind the piston, a conduit to receive the oil from said. secondchannel and terminating within the sleeve in front of the piston, andmeans to return the oil from the discharge-valve to said chamber.

5. In a compressor, the combination with a cylinder, a piston, a sleevesuction-valve surrounding the piston aud operated by the frictionthereof and a discharge-valve of a channel between said sleeve andcylinder forming an oil-cushion, a second channel about said sleeve inrear of the first channel to receive the oil escaping from theoil-cushion and prevent its escape behind the piston, a third channelabout said sleeve in front of the first channel to receive the oilescaping forwardly from the oil-cnshion, a conduit to receive the oilfrom said channels and terminating with the sleeve in front of thepiston, and means to return the oil from the discharge-valve to saidchamber.

This specification signed and witnessed this 20th day of November, A. D.1901.

WILLIAM J. FRANOKE. In presence of M. A. HARKINS, T. G. PHINNY.

